Pyrazolo and indazolo triazolyl stilbene disulfonic acids



United States Patent 2,989,527 PYRAZOLO AND INDAZOLO TRIAZOLYL STILBENE DISULFONI'C ACIDS Dennis Arthur William Adams, Leeds, and Asim Knmar Sarkar, 'Castleford, England, assignors to Hickson & Welch Limited, Castleford, England, a British company No Drawing. Filed Jan. 28, 1958, Ser. No. 711,547 Claims priority, application Great Britain Feb. 1, 1957 9 Claims. (Cl. 260240) This invention is concerned with improvements or relating to optical whitening agents and is more partlcularly concerned with certain new compounds for use as optical whitening agents. 7

Optical whitening agents have in recent years found extensive use in the treatment of textiles particularly during washing and are designed to counteract the yellow or off-white colour which white textiles may possess, especially after repeated Washing. Such optical whitening agents also tend to improve coloured textiles as they impart a general brightness to them. They are also widely used to impart whiteness to other material of cellulosic nature, particularly paper.

Optical whitening agents in general absorb light in the ultra violet range of the spectrum and emit in the visible spectrum, usually in the bluish green to bluish violet. These colours are, of course, complementary to colours in the yellow part of the spectrum and thus the fluorescence of such compounds in white material tends to counteract any yellowing such as, for example, that resulting from repeated washing of a white cotton or linen textile.

In general best results are obtained with optical whitening agents which give a shade of fluorescence which is complementary to that of the aged fibre, so that the colours will cancel each other out. In general, the most common ofiF-white shade of textiles resulting from ageing or repeated washing is yellow; a common optical whitening agent is therefore one that fluoresces blue.

However, a blue-fluorescent substance is found in practice not always to give the desired compensation, probably due to the presence of brownish tinges in the textile, with the result that it may be desirable to mix with the bluerfluorescent substance a substance having a more greenish fluorescence so as to obtain a more complete compensation. In other words in addition to a bluefluorescent substance a fluorescent substance having a greenish tinge is often desirable to shade the final colour.

It is important that the optical whitening agent should be substantive to the textiles being treated and if a compound is to be of the widest use as an optical whitening agent it should be substantive to both cellulosic and woollen textiles. The compounds should also be substantially stable when dyed onto the textile.

It is also of importance that an optical whitening agent should not be destroyed or removed by bleaching agents, that is, it should be bleach fast. Thus, fluorescent optical whitening agents are generally incorporated into soaps and synthetic detergents, which are marketed for household use and articles washed therewith are often subjected to bleaching with various agents for example sodium hypochlorite, or chlorine itself. It is therefore desirable that the optical whitening agent already on the fibre or in the treating solution should be affected as little as possible by the action of any bleaching agent which may be present.

Optical whitening agents should also possess a high fluorescence efliciency, that is, they should convert ultraviolet light to visible light with as little net absorption as possible, in order that the minimum amount of the agent 2,989,527. Patented June 20,

SOaH SOzH where A represents a residue of the formula:

CCCHI II II and [in which R is hydrogen or a hydrocarbon radical (which may be substituted other than by a chromophoric or auxochromic group), such as an alkyl, aralkyl or aryl group, and R is hydrogen or a hydrocarbon radical, (which may be substituted other than by a chromophoric or auxochromic group) such as an alkyl, aralkyl or-aryl group or is a hydroxyalkyl or a polyethanoxy group] and salts of such compounds, in particular water-soluble for example alkali-metal, e.g. sodium salts, can be used-with particular advantage as optical whitening agents as they possess a greenish blue fluorescence, good bleach fastness and high fluorescence efiiciency, and impart an attractive whitness to the detergent powder orsoap into which they are incorporated. 1

The compounds according to the invention have good aflinity for cellulosic material and in particular possess also a markedly better affinity for woollen textiles than many optical whitening agents hitherto prepared. This is unusual as few optical whitening agents possess reasonable afiinity for both cotton and woollen textiles.

Accordingly the invention comprises-such compounds, together with salts thereof, in particular water-soluble, for example alkali-metal, such as sodium, salts. The compounds according tothe present invention vcan with advantage be incorporated in compositions nor mally used for the treatment of textiles, for example detergents and soaps in solid or liquid form. They may also be incorporated in baths for the treatment of cellulosic or woollen materials during their production or for treatment of the finished textile article. In addition, the new compounds may also be incorporated in compositions. for the treatment of paper and photographic paper where high whiteness is necessary. The greenish fluorescence of the compounds according to the invention makes them particularly useful for the purpose of obtaining shading efiects.

According to a feature of the invention therefore there is provided a composition adapted for the treatmentjjo' f; textiles, in particular of cellulosic or woollen materials,"

comprising as optical whitening agent one or more compounds of the formula:

N A I N on=on N/|\A N N 30311 son; I

(where A has the meaning stated above) and salts thereof, in particular water-soluble, for example, alkalimetal, e.g. sodium salts. The invention also includes textiles, in particular cellulosic or woollen materials when treated with the above composition.

New compounds according to the invention which are preferred on account of their particularly favourable properties are those in which the groups R and R represent hydrogen or alkyl groups, preferably containing from lcarbon atoms, in particular methyl or ethyl groups. In compounds where A represents group I above then those compounds are preferred in which R is a substituted or unsubstituted aryl group, for example a halogen substituted or unsubstituted phenyl or tolyl group.

Compounds which are particularly preferred because of their advantageous properties are as follows:

4:4 bis (1' phenyl 3-methyl)-pyrazolo-(4":5"-

4-":5"')triazolyl-stilbene-Z:2-disulphonic acid and its disodium salt 4:4 bis (1" (p-tolyl)-3"'-methyl)-pyrazolo-(4":5-

4':5")-triazolyl-stilbene-2:2'-disulphonic acid and its disodium salt 4:4 bis (1"-(p-chlorophenyl)-3'-methyl)-pyrazolo- (4":5"-4":5"') triazolyl stilbene-2:2-disulphonic acid and its disodium salt 4:4 bis indazolo- (4":5"-6"':7"')-triazolyl-stilbene- 2:2'-disulphonic acid and its disodium salt The new compounds according to the invention can conveniently be prepared by oxidising a bis-o-amino azo dye of Formula II given below, and according to a further feature of the invention therefore we provide a process for the preparation of compounds of the general formula:

(where A has the above stated meaning) which comprises oxidising a bis-o-amino azo dye of the general formula:

NHTQG n=on SOgH SOzH and coupling the tetrazotized compound with a compound of the formula H3NA (in which A has the 4 above stated meaning). If desired the tetrazonium compound may be isolated.

In order that the invention may be more fully understood the following examples are given by way of illustration only:

EXAMPLE 1 9.4 g. of 4:4-diamino-stilbene-2:2'-disulphonic acid are dissolved in water by addition of sodium carbonate. The free acid of the diann'no-stilbene-disulphonic acid is precipitated in fine form by the addition of hydrochloric acid and ice. The suspension is then tetrazotised with 3.45 grams of sodium nitrite. The tetrazotised compound is filtered off,- washed and re-slurried in water and pyridine. To this slurry is added a solution of 8.7 g. of lphenyl-3-methyl-5-amino-pyrazole in aqueous hydrochlo- V ric acid. The mixture is made slightly basic by addition of pyridine. When the coupling is complete the dye is salted out and washed with brine.

The bis-azo dye so obtained is dissolved in pyridine and refluxed with a solution of 50 gms. of copper sulphate in water. When all the dye has been oxidized, the mixture is made acid with hydrochloric acid and the product filtered off and washed with water.

The product is crystallised from aqueous acetone.

When a piece of cotton or wool is washed with detergent or soap containing small amounts of the above prodnot, the fabric attains a much whiter and brighter appearance than when washed with soap or detergent not containing the above product.

EXAMPLE 2 Disodium 4,4'-bis-(1'-phenyl 3' methyl) pyrazolo- (4 ":5 "-4':5 ")-triaz0lyl-stilbene-2,2'-disulph0nate A solution of 9.25 parts of 4,4'-diaminostilbene-2,2- disulphonic acid, 2.05 gms. of sodium hydroxide and 3.45 parts of sodium nitrite in 150 parts of water is indirectly diazotised at 8-10 C., with 12.5 parts of concentrated hydrochloric acid. The suspension of the diazo compound is coupled at 10-l2 C. with a solution of 8.7 parts of 1-phenyl-3-methyl-5-aminopyrazole in 200 mls. dilute hydrochloric acid. A solution of parts of sodium acetate is added to control the pH during the coupling.

On completion of the coupling, the dye is filtered off, washed, dissolved in 50% aqueous alcohol and treated with 60 parts sodium hypochlorite solution at 7075 C. The product was filtered off and recrystallised from aqueous acetone.

EXAMPLE 3 Disodium 4,4'-bis-(1-(p-tolyl) -3" methyl) pyrazola- (4":5-4":5"')-triaz0lyl-stilbene-2,2"disulphonate A solution of 18.5 parts of 4,4-diaminostilbene-2,2- disulphonic acid 4.1 parts of sodium hydroxide and 6.9 parts of sodium nitrite in 300 parts of water is indirectly diazotised at 8-l0 C., with 25 parts of concentrated hydrochloric acid. The suspension of the diazo compound is coupled at l0-12 C. with a solution of 18.7 parts of l-(p-tolyl)-3-methyl-5-aminopyrazole in 300 parts dilute hydrochloric acid. A solution of 100 parts of sodium acetate is added to control the pH during the coupling.

On completion of the coupling, the dye is filtered off, washed, dissolved in 200 parts of pyridine and refluxed with 60 parts of copper sulphate and 75 parts of ammonia in 100 parts of water, for 3 hours.

On completion of the oxidation, the triazole is precipitated by acidification, converted to its sodium salt and recrystallised from aqueous pyridine.

EXAMPLE 4 Particularly suitable optical whitening agents are those Disodium 4,4-bis-(1-(p-chlor0phenyl)-3'-methyl)-py- P p in Examples aboverazolo(4":5"-4"':5"")-triazolyl-stilbene-2,2'-disulph0n- We claim: ate 1. A compound selected from the group consisting of A solution of 9.25 parts of 4,4-diaminostilbene-2,2-di- 5 compounds of the formulae Hio-o--o N -c---o-oni sulphonic acid, 2.05 parts of sodium hydroxide and 3.45 where R is selected from the group consisting of hydroparts of sodium nitrite in 150 parts of water is indirectly gen, an alkyl group contalmng from- 1-5 carbon atoms, diazotised at 8-10" 0., with 12.5 parts of concentrated a p y g p, a p nyl gr up, a yl gr up and hydrochloric acid. The suspension of the diazo coma chlorotollfl g p and 1 and 2 Selected from the pound is coupled at 10-12 c. Wlth a solution of 10.43 r up conslstmg of hydrogen an y group parts of 1-(p-chlorophenyl)-3-methyl-5+aminopyrazole tamlqg from carbon t and kali m tal salts in 175 parts of dilute hydrochloric acid. 100 parts of of sand g pp n sodium acetate solution are added to control the pH. P P Y PY On completion of the coupling, the dye is filterefcll off, d= 4 'tflawlyl stllbelle 232 dlsulphomc washed, and dissolved in 300 parts of pyridine, re uxed acl m With 30 parts of copper sulphate and parts of am- The dlsodlumjall'i'of 3 P Y monia in 50 parts of water. The triazole was precipi- P :5 4 mazolyl stllbflletated, after refluxing for 3 hours, by acidification, filtered 212 lP 3 m oil? and recrystallised from aqueous acetone. 35 0 a -SE o t gg gfilbggetliylz) -(11)i3;ru:-

phonic acid. EXAMPLE 5 5. The disodium salt of 4:4'-bis-(l"-(p-tolyl)-3"'- m methyl)-pyrazo1o-(4-":5"-4'":5"')-t1-iazo1yl-stilbene- Dlsodzum 4,4 -bls-mdazolo-(4 :5 -6 :7 )-trlazolyl-sttl- 2:2' di 1 i acicL bene-2,2-diswlphonate 6. 4:4 bis 1 (p chlorophenyl) 3 methyl)- A solution of 18.5 parts of 4,4-diaminostilbene-2,2'- g g f fig gj i 4 5 smbe disulphonic acid, parts of sodium hydroxide and 6.9 7. The disodium Salt of 4 4| (1n! p 1 p y parts of sodium mtrite in 300 parts of water 18 lndirectly m methyl) pyrawlo 5!") triazolyk diazotised at 8-10 (3., with 25 parts of concentrated ilb z zzdi lph i acid.

hydrochloric acid. The suspension of the diazo combis indazolo 6 ":7 uimlyb pound is coupled at Ill-12 C. with a solution of 13.3 Stflbene 2;2' disu1ph0nic acid parts of fi-aminoindazole and 10 parts of hydrochloric 9. The disodium salt of 4:4' 1 4n 5n acid in 200 parts of Water. A solution of 100 parts of 6w;7m) triaz1y1 stflbene 2:zr disulphonic acid sodium acetate is added to control the pH during the coupling. 1 h h th d fil d References Cited in the file of this patent On comp etion of t e coup mg, i e ye is tere UNI ofi, washed, and the wet cake dissolved in 400 parts of TED STATES PATENTS pyridine. This solution is refluxed for 3 hours with a 2,684,966 Keufar at a] July 1954 solution in parts of water of 60 parts of copper 5111- 55 2,713,057 Zweldlel' et July 1955 phate and excess ammonia and on completion of the 2,730,503 y p 1955 oxidation the crude tn'azole is precipitated by acidifica f 1956 tion. After reconversion to the disodium salt the product 53133 gi er et a i is recrystallised from aqueous pyridine in the presence 2809123 3 12 i 1957 Sdium hydmsulphile- 2:928:830 Adams et a1 11111134. '15: 1960 265,414 Switz l d A detergent composition containing an optical whiteer an Apr 1 ning agent according to the invention may be formulated OTHER REFERENCES as follows: Siegn'st: Soap and Chemical Specialties, vol. 31, No.

Percent 12, pages 58-60 (1955). Dodecylbenzene sodium sulphonate n 30 to %S.Annalen der Chemie, vol. 389, pages 337 Sodmm {netaslllcate Pentahydrate 25 o Michaelis et al.: Annalen der Chemie, vol. 354, page Tetrasodium pyrophosphate 25 1 2 1 7 Opt cal whitening agent Michaelis: Annalen der Ohemie, vol. 385, pages 15 to Sodium sulphate 19.95 19 (1911). i

-- Michaelis et al.: Annalen der Chemie, vol. 407, pages 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS OF THE FORMULAE 